Updating array element in a collection in Meteor

Question

I'm trying to find and update an element within an array in a mongodb collection in a meteor app.

Every element in the array is an object that has an "_id" attribute, so I'm using mongo's '$' pointer:

Collection.update({things._id: currentThingId},{$set: {things.$.value: aGivenValue}});

However, it keeps throwing me an "Unexpected ." exception, pointing to the line where I use "things**.**_id". I followed mongodb documentation, so any chance meteor has some limitatiob with this mongo functionality?

You forgot the quotes around "things._id" and co. It has to look like {'things._id' : currentThingId}. You can't use . in a property name outside a string. — Kyll
You right. I tried to enclose with "" before asking here, but did forgot the things.$.value. Thanks! — Maboo

chridam chridam · Accepted Answer · 2015-05-23T15:24:06

You need to enclose the field with quotes when using the dot notation to access an element of an array by the zero-based index position, bearing in mind that the positional $ operator limits the contents of an array from the query results to contain only the first element matching the query document. Thus your final update query should look like:

Collection.update({"things._id": currentThingId},{$set: {"things.$.value": aGivenValue}});

Updating array element in a collection in Meteor

2 Answers